﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

using System.Runtime.InteropServices;
using System.Diagnostics;

namespace JJDock
{
    static class Program
    {
        private const int WH_KEYBOARD_LL = 13;
        private const int WM_KEYDOWN = 0x0100;
        private static LowLevelKeyboardProc _proc = HookCallback;
        private static IntPtr _hookID = IntPtr.Zero;
        public static bool ScreenCheck = false;
        public static bool ScreenCheck_s = true;

        /// <summary>
        /// 해당 응용 프로그램의 주 진입점입니다.
        /// </summary>
        [STAThread]
        static void Main()
        {
            System.Diagnostics.Process[] myProc = System.Diagnostics.Process.GetProcessesByName("JJDock");
            // 여기서 Mulpumi는 프로젝트 속성의 프로젝트 이름.

            // 중복 실행 방지.
            if (myProc.Length < 2)
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);

                _hookID = SetHook(_proc);
                Application.Run(new Form1());
                UnhookWindowsHookEx(_hookID);
                
            }
            else
            {
                //MessageBox.Show("이미 프로그램이 실행되어 있습니다.");
                Application.Exit();
            }
        }

        private static IntPtr SetHook(LowLevelKeyboardProc proc)
        {
            using (Process curProcess = Process.GetCurrentProcess())
            using (ProcessModule curModule = curProcess.MainModule)
            {
                return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                    GetModuleHandle(curModule.ModuleName), 0);
            }
        }

        private delegate IntPtr LowLevelKeyboardProc(
            int nCode, IntPtr wParam, IntPtr lParam);

        private static IntPtr HookCallback(
            int nCode, IntPtr wParam, IntPtr lParam)
        {
            if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
            {
                int vkCode = Marshal.ReadInt32(lParam);
                //if (Keys.D == (Keys)vkCode && Keys.LWin == Control.ModifierKeys)// || Keys.RWin == Control.ModifierKeys)
                if (Keys.F12 == (Keys)vkCode && Keys.Control == Control.ModifierKeys)
                {
                    if (ScreenCheck_s)
                    {
                        ScreenCheck = true;
                        ScreenCheck_s = false;
                    }
                    else
                    {
                        ScreenCheck = false;
                        ScreenCheck_s = true;
                    }
                    
                }
            }
            return CallNextHookEx(_hookID, nCode, wParam, lParam);
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr SetWindowsHookEx(int idHook,
            LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool UnhookWindowsHookEx(IntPtr hhk);

        [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
            IntPtr wParam, IntPtr lParam);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);
    }
}
